But here in South Korea, human rights advocates, bloggers and Christian pastors are accusing them of needlessly endangering the very people they tried to cover: North Korean refugees and the activists who help them.

The accusations stem from a central fear repeated in newspapers and blogs here: that the notes and videotapes the journalists gathered in China before their ill-fated venture to the border fell into the hands of the authorities, potentially compromising the identities of refugees and activists dedicated to spiriting people out of the North.

The Rev. Lee Chan-woo, a South Korean pastor, said the police raided his home in China on March 19, four days after the journalists visited and filmed a secret site where he looked after children of North Korean refugee women. He said that he was then deported in early April and that his five secret homes for refugees were shut down. The children, he said, were dispersed to family members in China, who could not afford to take care of them.

“The Chinese cited scenes from films confiscated from the journalists when they interrogated me,” said Mr. Lee, 70. As evidence of the ordeal, he provided documents he said the Chinese police gave him after the raid.

“The reporters visited our place with a noble cause,” he added. “I did my best to help them. But I wonder how they could be so careless in handling their tapes and notebooks. They should have known that if they were caught, they would suffer for sure, but also many others would be hurt because of them.”

The Rev. Chun Ki-won, the chief pastor of the Durihana Mission that Mr. Lee works with, said that two of the women interviewed by the American journalists fled China after being told about the arrests, frightened of being repatriated to North Korea and put in labor camps. Another interviewee was still on the run in China, he said.

“We could not find out whether they filmed any other refugees we don’t know of,” Mr. Chun said. “If that’s the case, we have to find them, provided it’s not too late already. But the American reporters are not talking to us.”

Many elements of Ms. Ling and Ms. Lee’s reporting trip remain shrouded in mystery. Neither their employer, Current TV, nor the journalists have revealed details of their work or the circumstances under which they were captured.

Brent Marcus, a spokesman for Current TV, said, “We’re concerned about the situation that has evolved with Lee Chan-woo and the Durihana Mission.”

But he said “many of the details” in the pastors’ accounts were “not correct.” When Ms. Lee and Ms. Ling have recovered enough to tell their story, he said, it will differ from the pastors’ versions. E-mail messages to Ms. Lee and a representative who has been handling public relations for the reporters’ families were not answered.

According to Durihana, the Current TV crew met with Mr. Chun, the chief pastor, in Seoul on March 13, asking for help covering the plight of North Korean refugees in China. Mr. Chun said he put them in touch with Mr. Lee and a Korean guide in China.

An error has occurred. Please try again later.

You are already subscribed to this email.

On March 15, the crew met Mr. Lee in Yanji, a Chinese town near the northeastern border with North Korea, he said, but seeming lapses in security bothered him. For one, he said, they called his home telephone in Yanji — a serious breach of protocol for activists who operate under the constant fear of being monitored by the Chinese police.

The activists, missionaries and smugglers who help shuttle people out of North Korea have moved about 20,000 North Korean refugees through China, mostly to South Korea. Some operate with a political agenda to undermine the North Korean government, and some are driven by religious passion to convert North Koreans to Christianity.

Mr. Lee said the American crew asked to visit one of five secret homes where he looked after 20 children, ages 5 to 13. They were the children of North Korean women who had been lured by human traffickers with promises of food and then sold to Chinese men, he said.

Mr. Lee said he first asked the journalists not to film the children. When they assured him that they would obscure parts of the footage, like faces, Mr. Lee said he relaxed a bit. But he said he did not know until later that the crew asked children to face the camera and speak to their mothers, whom they had not seen for a long time.

“After they left,” he said, “the children told me excitedly about being filmed.”

The cameraman, Mr. Koss, declined to answer specific questions about the trip until Ms. Ling and Ms. Lee had spoken first. Still, he said, he was amazed by “how many untrue stories have been published in the last five months” and how “when there is silence, fantasy answers to fill in empty spaces.”

But here in South Korea, where the dangers of the China-North Korea border zone are well known, the American journalists’ venture has been criticized by many as foolhardy.

“We can assume that the journalists’ guide compromised every source,” said Joo Sung-ha, a North Korean defector who works in Seoul as a newspaper reporter.

In his blog, Mr. Joo has berated the American reporters, urging them to “shed their martyrdom image.” In a separate interview, Mr. Joo said he was also “disgusted” by the way “some American media are giving them some kind of hero’s welcome home.”

“Since their return,” he added, “they haven’t said a peep about the fate of the people they have endangered, though unintentionally.”

One human rights official in Seoul, who makes frequent excursions to China to interview North Korean refugees and whose work requires anonymity, complained: “I had to suspend my own trips and work in China because of the tension” created by the episode.

Mr. Chun, the chief pastor, also raised concerns that the events might discourage future reporting on refugees. “Getting arrested and repatriated to the North is almost an everyday event for these poor refugees,” he said. “The difference is that they don’t get the kind of attention the American journalists did.”

A version of this article appears in print on , on Page A4 of the New York edition with the headline: In South Korea, Freed U.S. Journalists Come Under Harsh Criticism. Order Reprints|Today's Paper|Subscribe